Researchers at the University of Artaud in Finland, for the first time developed a plasma laser, which can operate at a frequency of visible light and can use the so-called dark mode.

The lasers operate at a wavelength that is 1,000 times smaller than the thickness of human hair. The light-trapping lifetime at such a small size is so short that only a few tens or hundreds of revolutions of the light are made at this time. This study opens up new prospects for chip research with coherent light sources, such as miniaturization and ultrafast 50mw laser pointer.

The laser operation in this work is based on silver nanoparticles, and the particles are placed in a periodic array. The feedback of the laser signal with the conventional is through the ordinary mirror of the laser compared to that of the nanometer laser which utilizes the radiation coupling between the silver nanoparticles. These 100 nanometer-sized particles act as tiny antennas. To produce high-intensity lasers, the distance between the particles is matched with the wavelength, and all the radiation of the particle array is consistent. Organic fluorescent molecules are used to provide the required input energy (gain) of the high power laser pointer.

One of the main challenges in achieving such lasers is that, for gain, at such a small size, light may not be present for long enough. Researchers have found a way to solve this potential problem: they produce a laser in the dark mode.

"Dark mode can be intuitively understood with conventional antennas: single antenna, where the driving current is applied, the radiation is very intense, and if the opposite current is applied and placed very close to each other, the radiation from the two antennas "Explains Professor P I IVI T RM RM of the Faculty. "The dark pattern in the nanoparticle array produces similar phase currents in each nanoparticle, but now the frequency of the visible light can be achieved," she continues.

"Dark mode is attractive, for this application requires low power consumption, but without any skill, dark mode 300mw laser pointer will be useless, because the light is trapped in the nanoparticle array can not leave, The research scientist Tommi Hakala added. "Using the small size of the array, however, we found a guide path for light, pointing to the edge of the array where the behavior of nanoparticles began to become more and more like an ordinary antenna that radiates into the outer world," says Dr. Heikki Rekola Said.